This is a preparation for the following patch to make review simpler.
While the primary motivation is a bug fix, this also simplifies the fast
path, although the moved code is only enabled when cpusets are in use.

Link: http://lkml.kernel.org/r/20170120103843.24587-4-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Ganapatrao Kulkarni <gpkulkarni@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Ganapatrao Kulkarni reported that the LTP test cpuset01 in stress mode
triggers OOM killer in few seconds, despite lots of free memory.  The
test attempts to repeatedly fault in memory in one process in a cpuset,
while changing allowed nodes of the cpuset between 0 and 1 in another
process.

One possible cause is that in the fast path we find the preferred
zoneref according to current mems_allowed, so that it points to the
middle of the zonelist, skipping e.g.  zones of node 1 completely.  If
the mems_allowed is updated to contain only node 1, we never reach it in
the zonelist, and trigger OOM before checking the cpuset_mems_cookie.

This patch fixes the particular case by redoing the preferred zoneref
search if we switch back to the original nodemask.  The condition is
also slightly changed so that when the last non-root cpuset is removed,
we don't miss it.

Note that this is not a full fix, and more patches will follow.

Link: http://lkml.kernel.org/r/20170120103843.24587-3-vbabka@suse.cz
Fixes: 682a3385 ("mm, page_alloc: inline the fast path of the zonelist iterator")
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Reported-by: NGanapatrao Kulkarni <gpkulkarni@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "fix premature OOM regression in 4.7+ due to cpuset races".

This is v2 of my attempt to fix the recent report based on LTP cpuset
stress test [1].  The intention is to go to stable 4.9 LTSS with this,
as triggering repeated OOMs is not nice.  That's why the patches try to
be not too intrusive.

Unfortunately why investigating I found that modifying the testcase to
use per-VMA policies instead of per-task policies will bring the OOM's
back, but that seems to be much older and harder to fix problem.  I have
posted a RFC [2] but I believe that fixing the recent regressions has a
higher priority.

Longer-term we might try to think how to fix the cpuset mess in a better
and less error prone way.  I was for example very surprised to learn,
that cpuset updates change not only task->mems_allowed, but also
nodemask of mempolicies.  Until now I expected the parameter to
alloc_pages_nodemask() to be stable.  I wonder why do we then treat
cpusets specially in get_page_from_freelist() and distinguish HARDWALL
etc, when there's unconditional intersection between mempolicy and
cpuset.  I would expect the nodemask adjustment for saving overhead in
g_p_f(), but that clearly doesn't happen in the current form.  So we
have both crazy complexity and overhead, AFAICS.

[1] https://lkml.kernel.org/r/CAFpQJXUq-JuEP=QPidy4p_=FN0rkH5Z-kfB4qBvsf6jMS87Edg@mail.gmail.com
[2] https://lkml.kernel.org/r/7c459f26-13a6-a817-e508-b65b903a8378@suse.cz

This patch (of 4):

Since commit c33d6c06 ("mm, page_alloc: avoid looking up the first
zone in a zonelist twice") we have a wrong check for NULL preferred_zone,
which can theoretically happen due to concurrent cpuset modification.  We
check the zoneref pointer which is never NULL and we should check the zone
pointer.  Also document this in first_zones_zonelist() comment per Michal
Hocko.

Fixes: c33d6c06 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice")
Link: http://lkml.kernel.org/r/20170120103843.24587-2-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Ganapatrao Kulkarni <gpkulkarni@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a system panics, the "Rebooting in X seconds.." message is never
printed because it lacks a new line.  Fix it.

Link: http://lkml.kernel.org/r/20170119114751.2724-1-jslaby@suse.czSigned-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Copying color maps to userspace doesn't check the value of to->start,
which will cause kernel heap buffer OOB read due to signedness wraps.

CVE-2016-8405

Link: http://lkml.kernel.org/r/20170105224249.GA50925@beast
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NKees Cook <keescook@chromium.org>
Reported-by: Peter Pi (@heisecode) of Trend Micro
Cc: Min Chong <mchong@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The build of frv allmodconfig was failing with the error:
lib/atomic64_test.c:209:9: error:

	implicit declaration of function 'atomic64_add_unless'

All the atomic64 operations were defined in frv, but
atomic64_add_unless() was not done.

Implement atomic64_add_unless() as done in other arches.

Link: http://lkml.kernel.org/r/1484781236-6698-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by: NSudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit be97a41b ("mm/mempolicy.c: merge alloc_hugepage_vma to
alloc_pages_vma") alloc_pages_vma() can potentially free a mempolicy by
mpol_cond_put() before accessing the embedded nodemask by
__alloc_pages_nodemask().  The commit log says it's so "we can use a
single exit path within the function" but that's clearly wrong.  We can
still do that when doing mpol_cond_put() after the allocation attempt.

Make sure the mempolicy is not freed prematurely, otherwise
__alloc_pages_nodemask() can end up using a bogus nodemask, which could
lead e.g.  to premature OOM.

Fixes: be97a41b ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma")
Link: http://lkml.kernel.org/r/20170118141124.8345-1-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>	[4.0+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The newly introduced warning in radix_tree_free_nodes() was testing the
wrong variable; it should have been 'old' instead of 'node'.

Fixes: ea07b862 ("mm: workingset: fix use-after-free in shadow node shrinker")
Link: http://lkml.kernel.org/r/20170118163746.GA32495@cmpxchg.orgSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit bc3e53f6 ("mm: distinguish between mlocked and pinned pages")
added VmPin in /proc/<pid>/status.  Report that in
Documentation/filesystems/proc.txt

Also move Umask after Name to keep correct order.

Link: http://lkml.kernel.org/r/20170114201219.30387-1-fabf@skynet.beSigned-off-by: NFabian Frederick <fabf@skynet.be>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When memory.move_charge_at_immigrate is enabled and precharges are
depleted during move, mem_cgroup_move_charge_pte_range() will attempt to
increase the size of the precharge.

Prevent precharges from ever looping by setting __GFP_NORETRY.  This was
probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is
pointless as written.

Fixes: 0029e19e ("mm: memcontrol: remove explicit OOM parameter in charge path")
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701130208510.69402@chino.kir.corp.google.comSigned-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have seen proc_pid_readdir() invocations holding cpu for more than 50
ms.  Add a cond_resched() to be gentle with other tasks.

[akpm@linux-foundation.org: coding style fix]
Link: http://lkml.kernel.org/r/1484238380.15816.42.camel@edumazet-glaptop3.roam.corp.google.comSigned-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 73e64c51 ("mm, compaction: allow compaction for GFP_NOFS
requests") changed compation to skip FS pages if not explicitly allowed
to touch them, but missed to update the CMA compact_control.

This leads to a very high isolation failure rate, crippling performance
of CMA even on a lightly loaded system.  Re-allow CMA to compact FS
pages by setting the correct GFP flags, restoring CMA behavior and
performance to the kernel 4.9 level.

Fixes: 73e64c51 (mm, compaction: allow compaction for GFP_NOFS requests)
Link: http://lkml.kernel.org/r/20170113115155.24335-1-l.stach@pengutronix.deSigned-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently when trace is enabled (e.g.  slub_debug=T,kmalloc-128 ) the
trace messages are mostly output at KERN_INFO.  However the trace code
also calls print_section() to hexdump the head of a free object.  This
is hard coded to use KERN_ERR, meaning the console is deluged with trace
messages even if we've asked for quiet.

Fix this the obvious way but adding a level parameter to
print_section(), allowing calls from the trace code to use the same
trace level as other trace messages.

Link: http://lkml.kernel.org/r/20170113154850.518-1-daniel.thompson@linaro.orgSigned-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With >=32 CPUs the userfaultfd selftest triggered a graceful but
unexpected SIGBUS because VM_FAULT_RETRY was returned by
handle_userfault() despite the UFFDIO_COPY wasn't completed.

This seems caused by rwsem waking the thread blocked in
handle_userfault() and we can't run up_read() before the wait_event
sequence is complete.

Keeping the wait_even sequence identical to the first one, would require
running userfaultfd_must_wait() again to know if the loop should be
repeated, and it would also require retaking the rwsem and revalidating
the whole vma status.

It seems simpler to wait the targeted wakeup so that if false wakeups
materialize we still wait for our specific wakeup event, unless of
course there are signals or the uffd was released.

Debug code collecting the stack trace of the wakeup showed this:

  $ ./userfaultfd 100 99999
  nr_pages: 25600, nr_pages_per_cpu: 800
  bounces: 99998, mode: racing ver poll, userfaults: 32 35 90 232 30 138 69 82 34 30 139 40 40 31 20 19 43 13 15 28 27 38 21 43 56 22 1 17 31 8 4 2
  bounces: 99997, mode: rnd ver poll, Bus error (core dumped)

    save_stack_trace+0x2b/0x50
    try_to_wake_up+0x2a6/0x580
    wake_up_q+0x32/0x70
    rwsem_wake+0xe0/0x120
    call_rwsem_wake+0x1b/0x30
    up_write+0x3b/0x40
    vm_mmap_pgoff+0x9c/0xc0
    SyS_mmap_pgoff+0x1a9/0x240
    SyS_mmap+0x22/0x30
    entry_SYSCALL_64_fastpath+0x1f/0xbd
    0xffffffffffffffff
    FAULT_FLAG_ALLOW_RETRY missing 70
  CPU: 24 PID: 1054 Comm: userfaultfd Tainted: G        W       4.8.0+ #30
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    dump_stack+0xb8/0x112
    handle_userfault+0x572/0x650
    handle_mm_fault+0x12cb/0x1520
    __do_page_fault+0x175/0x500
    trace_do_page_fault+0x61/0x270
    do_async_page_fault+0x19/0x90
    async_page_fault+0x25/0x30

This always happens when the main userfault selftest thread is running
clone() while glibc runs either mprotect or mmap (both taking mmap_sem
down_write()) to allocate the thread stack of the background threads,
while locking/userfault threads already run at full throttle and are
susceptible to false wakeups that may cause handle_userfault() to return
before than expected (which results in graceful SIGBUS at the next
attempt).

This was reproduced only with >=32 CPUs because the loop to start the
thread where clone() is too quick with fewer CPUs, while with 32 CPUs
there's already significant activity on ~32 locking and userfault
threads when the last background threads are started with clone().

This >=32 CPUs SMP race condition is likely reproducible only with the
selftest because of the much heavier userfault load it generates if
compared to real apps.

We'll have to allow "one more" VM_FAULT_RETRY for the WP support and a
patch floating around that provides it also hidden this problem but in
reality only is successfully at hiding the problem.

False wakeups could still happen again the second time
handle_userfault() is invoked, even if it's a so rare race condition
that getting false wakeups twice in a row is impossible to reproduce.
This full fix is needed for correctness, the only alternative would be
to allow VM_FAULT_RETRY to be returned infinitely.  With this fix the WP
support can stick to a strict "one more" VM_FAULT_RETRY logic (no need
of returning it infinite times to avoid the SIGBUS).

Link: http://lkml.kernel.org/r/20170111005535.13832-2-aarcange@redhat.comSigned-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Reported-by: NShubham Kumar Sharma <shubham.kumar.sharma@oracle.com>
Tested-by: NMike Kravetz <mike.kravetz@oracle.com>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

gcc-7 produces a harmless false-postive warning about a possible NULL
pointer access:

  drivers/memstick/core/memstick.c: In function 'h_memstick_read_dev_id':
  drivers/memstick/core/memstick.c:309:3: error: argument 2 null where non-null expected [-Werror=nonnull]
     memcpy(mrq->data, buf, mrq->data_len);

This can't happen because the caller sets the command to 'MS_TPC_READ_REG',
which causes the data direction to be 'READ' and the NULL pointer not
accessed.

As a simple workaround for the warning, we can pass a pointer to the
data that we actually want to read into.  This is not needed here, but
also harmless, and lets the compiler know that the access is ok.

Link: http://lkml.kernel.org/r/20170111144143.548867-1-arnd@arndb.deSigned-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On an overloaded system, it is possible that a change in the watchdog
threshold can be delayed long enough to trigger a false positive.

This can easily be achieved by having a cpu spinning indefinitely on a
task, while another cpu updates watchdog threshold.

What happens is while trying to park the watchdog threads, the hrtimers
on the other cpus trigger and reprogram themselves with the new slower
watchdog threshold.  Meanwhile, the nmi watchdog is still programmed
with the old faster threshold.

Because the one cpu is blocked, it prevents the thread parking on the
other cpus from completing, which is needed to shutdown the nmi watchdog
and reprogram it correctly.  As a result, a false positive from the nmi
watchdog is reported.

Fix this by setting a park_in_progress flag to block all lockups until
the parking is complete.

Fix provided by Ulrich Obergfell.

[akpm@linux-foundation.org: s/park_in_progress/watchdog_park_in_progress/]
Link: http://lkml.kernel.org/r/1481041033-192236-1-git-send-email-dzickus@redhat.comSigned-off-by: NDon Zickus <dzickus@redhat.com>
Reviewed-by: NAaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As reported by Arnd:

  https://lkml.org/lkml/2017/1/10/756

Compiling with the following configuration:

  # CONFIG_EXT2_FS is not set
  # CONFIG_EXT4_FS is not set
  # CONFIG_XFS_FS is not set
  # CONFIG_FS_IOMAP depends on the above filesystems, as is not set
  CONFIG_FS_DAX=y

generates build warnings about unused functions in fs/dax.c:

  fs/dax.c:878:12: warning: `dax_insert_mapping' defined but not used [-Wunused-function]
   static int dax_insert_mapping(struct address_space *mapping,
              ^~~~~~~~~~~~~~~~~~
  fs/dax.c:572:12: warning: `copy_user_dax' defined but not used [-Wunused-function]
   static int copy_user_dax(struct block_device *bdev, sector_t sector, size_t size,
              ^~~~~~~~~~~~~
  fs/dax.c:542:12: warning: `dax_load_hole' defined but not used [-Wunused-function]
   static int dax_load_hole(struct address_space *mapping, void **entry,
              ^~~~~~~~~~~~~
  fs/dax.c:312:14: warning: `grab_mapping_entry' defined but not used [-Wunused-function]
   static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
                ^~~~~~~~~~~~~~~~~~

Now that the struct buffer_head based DAX fault paths and I/O path have
been removed we really depend on iomap support being present for DAX.
Make this explicit by selecting FS_IOMAP if we compile in DAX support.

This allows us to remove conditional selections of FS_IOMAP when FS_DAX
was present for ext2 and ext4, and to remove an #ifdef in fs/dax.c.

Link: http://lkml.kernel.org/r/1484087383-29478-1-git-send-email-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit 19be0eaf ("mm: remove gup_flags FOLL_WRITE games from
__get_user_pages()"), the mm code was changed from unsetting FOLL_WRITE
after a COW was resolved to setting the (newly introduced) FOLL_COW
instead.  Simultaneously, the check in gup.c was updated to still allow
writes with FOLL_FORCE set if FOLL_COW had also been set.

However, a similar check in huge_memory.c was forgotten.  As a result,
remote memory writes to ro regions of memory backed by transparent huge
pages cause an infinite loop in the kernel (handle_mm_fault sets
FOLL_COW and returns 0 causing a retry, but follow_trans_huge_pmd bails
out immidiately because `(flags & FOLL_WRITE) && !pmd_write(*pmd)` is
true.

While in this state the process is stil SIGKILLable, but little else
works (e.g.  no ptrace attach, no other signals).  This is easily
reproduced with the following code (assuming thp are set to always):

    #include <assert.h>
    #include <fcntl.h>
    #include <stdint.h>
    #include <stdio.h>
    #include <string.h>
    #include <sys/mman.h>
    #include <sys/stat.h>
    #include <sys/types.h>
    #include <sys/wait.h>
    #include <unistd.h>

    #define TEST_SIZE 5 * 1024 * 1024

    int main(void) {
      int status;
      pid_t child;
      int fd = open("/proc/self/mem", O_RDWR);
      void *addr = mmap(NULL, TEST_SIZE, PROT_READ,
                        MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
      assert(addr != MAP_FAILED);
      pid_t parent_pid = getpid();
      if ((child = fork()) == 0) {
        void *addr2 = mmap(NULL, TEST_SIZE, PROT_READ | PROT_WRITE,
                           MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
        assert(addr2 != MAP_FAILED);
        memset(addr2, 'a', TEST_SIZE);
        pwrite(fd, addr2, TEST_SIZE, (uintptr_t)addr);
        return 0;
      }
      assert(child == waitpid(child, &status, 0));
      assert(WIFEXITED(status) && WEXITSTATUS(status) == 0);
      return 0;
    }

Fix this by updating follow_trans_huge_pmd in huge_memory.c analogously
to the update in gup.c in the original commit.  The same pattern exists
in follow_devmap_pmd.  However, we should not be able to reach that
check with FOLL_COW set, so add WARN_ONCE to make sure we notice if we
ever do.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170106015025.GA38411@juliacomputing.comSigned-off-by: NKeno Fischer <keno@juliacomputing.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

online_{kernel|movable} is used to change the memory zone to
ZONE_{NORMAL|MOVABLE} and online the memory.

To check that memory zone can be changed, zone_can_shift() is used.
Currently the function returns minus integer value, plus integer
value and 0. When the function returns minus or plus integer value,
it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}.

But when the function returns 0, there are two meanings.

One of the meanings is that the memory zone does not need to be changed.
For example, when memory is in ZONE_NORMAL and onlined by online_kernel
the memory zone does not need to be changed.

Another meaning is that the memory zone cannot be changed. When memory
is in ZONE_NORMAL and onlined by online_movable, the memory zone may
not be changed to ZONE_MOVALBE due to memory online limitation(see
Documentation/memory-hotplug.txt). In this case, memory must not be
onlined.

The patch changes the return type of zone_can_shift() so that memory
online operation fails when memory zone cannot be changed as follows:

Before applying patch:
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  7864320
           managed  7864320
   # echo online_movable > memory4097/state
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  8388608
           managed  8388608

   online_movable operation succeeded. But memory is onlined as
   ZONE_NORMAL, not ZONE_MOVABLE.

After applying patch:
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  7864320
           managed  7864320
   # echo online_movable > memory4097/state
   bash: echo: write error: Invalid argument
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  7864320
           managed  7864320

   online_movable operation failed because of failure of changing
   the memory zone from ZONE_NORMAL to ZONE_MOVABLE

Fixes: df429ac0 ("memory-hotplug: more general validation of zone during online")
Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.comSigned-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: NReza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull tile bugfix from Chris Metcalf:
 "This avoids an issue with short userspace reads for regset via ptrace"

* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile/ptrace: Preserve previous registers for short regset write

Pull GPIO fix from Linus Walleij:
 "A single lockdep fix, nothing else going on. This makes lockdep
  noiseless and work properly with threaded GPIO IRQchips.

  Summary:

  Fix a lockdep issue: the threaded irqchips also need their unique key,
  and take this opportunity to get rid of the horrible macro and replace
  it with a static inline"

* tag 'gpio-v4.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: provide lockdep keys for nested/unnested irqchips

Pull drm fixes from Dave Airlie:
 "drm fixes across the board.

  Okay holidays and LCA kinda caught up with me, I thought I'd get some
  of this dequeued last week, but Hobart was sunny and warm and not all
  gloomy and rainy as usual.

  This is a bit large, but not too much considering it's two weeks stuff
  from AMD and Intel.

  core:
   - one locking fix that helps with dynamic suspend/resume races

  i915:
   - mostly GVT updates, GVT was a recent introduction so fixes for it
     shouldn't cause any notable side effects.

  amdgpu:
   - a bunch of fixes for GPUs with a different memory controller design
     that need different firmware.

  exynos:
   - decon regression fixes

  msm:
   - two regression fixes

  etnaviv:
   - a workaround for an mmu bug that needs a lot more work.

  virtio:
   - sparse fix, and a maintainers update"

* tag 'drm-fixes-for-v4.10-rc6' of git://people.freedesktop.org/~airlied/linux: (56 commits)
  drm/exynos/decon5433: set STANDALONE_UPDATE_F on output enablement
  drm/exynos/decon5433: fix CMU programming
  drm/exynos/decon5433: do not disable video after reset
  drm/i915: Ignore bogus plane coordinates on SKL when the plane is not visible
  drm/i915: Remove WaDisableLSQCROPERFforOCL KBL workaround.
  drm/amdgpu: add support for new hainan variants
  drm/radeon: add support for new hainan variants
  drm/amdgpu: change clock gating mode for uvd_v4.
  drm/amdgpu: fix program vce instance logic error.
  drm/amdgpu: fix bug set incorrect value to vce register
  Revert "drm/amdgpu: Only update the CUR_SIZE register when necessary"
  drm/msm: fix potential null ptr issue in non-iommu case
  drm/msm/mdp5: rip out plane->pending tracking
  drm/exynos/decon5433: set STANDALONE_UPDATE_F also if planes are disabled
  drm/exynos/decon5433: update shadow registers iff there are active windows
  drm/i915/gvt: rewrite gt reset handler using new function intel_gvt_reset_vgpu_locked
  drm/i915/gvt: fix vGPU instance reuse issues by vGPU reset function
  drm/i915/gvt: introduce intel_vgpu_reset_mmio() to reset mmio space
  drm/i915/gvt: move mmio init/clean function to mmio.c
  drm/i915/gvt: introduce intel_vgpu_reset_cfg_space to reset configuration space
  ...

drm-qemu: virtio sparse fix, MAINTAINERS updates.

* tag 'drm-qemu-20170110' of git://git.kraxel.org/linux:
  drm: flip cirrus driver status to "obsolete".
  drm: update MAINTAINERS for qemu drivers (bochs, cirrus, qxl, virtio-gpu)
  drm/virtio: fix framebuffer sparse warning

a single fix for a FE hang after IOVA rollover on GC3000. This isn't
pretty, but is the minimal fix for the issue. A larger rework of the
code, that will also fix this issue properly, is currently in the works,
but that needs to wait for at least the next feature pull.

* 'drm-etnaviv-fixes' of https://git.pengutronix.de/git/lst/linux:
  drm/etnaviv: trick drm_mm into giving out a low IOVA

Merge branch 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes

Just regression fixups to resolve page fault issue of DECON device.

* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos/decon5433: set STANDALONE_UPDATE_F on output enablement
  drm/exynos/decon5433: fix CMU programming
  drm/exynos/decon5433: do not disable video after reset
  drm/exynos/decon5433: set STANDALONE_UPDATE_F also if planes are disabled
  drm/exynos/decon5433: update shadow registers iff there are active windows

A little bigger than usual since it's two weeks worth.  Highlights:
- Add support for new smc firmware on some new hainan variants
- add support for SI chips that require special mc firmware
- remove workarounds for issues fixed by new mc firmware
- fix a regression in cursor handling
- various VCE fixes
- fix for UVD clockgating

* 'drm-fixes-4.10' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: add support for new hainan variants
  drm/radeon: add support for new hainan variants
  drm/amdgpu: change clock gating mode for uvd_v4.
  drm/amdgpu: fix program vce instance logic error.
  drm/amdgpu: fix bug set incorrect value to vce register
  Revert "drm/amdgpu: Only update the CUR_SIZE register when necessary"
  drm/amd/powerplay: refine vce dpm update code on Cz.
  drm/amdgpu: fix vm_fault_stop on gfx6
  drm/amd/powerplay: fix vce cg logic error on CZ/St.
  drm/radeon: drop the mclk quirk for hainan
  drm/radeon: drop oland quirks
  drm/amdgpu: drop the mclk quirk for hainan
  drm/amdgpu: drop oland quirks
  drm/amdgpu/si: load special ucode for certain MC configs
  drm/radeon/si: load special ucode for certain MC configs

* 'msm-fixes-4.10-rc4' of git://people.freedesktop.org/~robclark/linux:
  drm/msm: fix potential null ptr issue in non-iommu case
  drm/msm/mdp5: rip out plane->pending tracking

A few more core fixes.

* tag 'drm-misc-fixes-2017-01-13' of git://anongit.freedesktop.org/git/drm-misc:
  drm/probe-helpers: Drop locking from poll_enable
  drm: Fix broken VT switch with video=1366x768 option
  drm: Schedule the output_poll_work with 1s delay if we have delayed event

Merge tag 'drm-intel-fixes-2017-01-19' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes

More GVT-g stuff than I'd like at this stage, but then again that's
pretty new and isolated so I'm not too worried.

* tag 'drm-intel-fixes-2017-01-19' of git://anongit.freedesktop.org/git/drm-intel: (26 commits)
  drm/i915: Ignore bogus plane coordinates on SKL when the plane is not visible
  drm/i915: Remove WaDisableLSQCROPERFforOCL KBL workaround.
  drm/i915/gvt: rewrite gt reset handler using new function intel_gvt_reset_vgpu_locked
  drm/i915/gvt: fix vGPU instance reuse issues by vGPU reset function
  drm/i915/gvt: introduce intel_vgpu_reset_mmio() to reset mmio space
  drm/i915/gvt: move mmio init/clean function to mmio.c
  drm/i915/gvt: introduce intel_vgpu_reset_cfg_space to reset configuration space
  drm/i915/gvt: move cfg space inititation function to cfg_space.c
  drm/i915/gvt: introuduce intel_vgpu_reset_gtt() to reset gtt
  drm/i915/gvt: introudce intel_vgpu_reset_resource() to reset vgpu resource state
  drm/i915: Fix phys pwrite for struct_mutex-less operation
  drm/i915: Clear ret before unbinding in i915_gem_evict_something()
  drm/i915/gvt: cleanup GFP flags
  drm/i915/gvt/kvmgt: return meaningful error for vgpu creating failure
  drm/i915/gvt: cleanup opregion memory allocation code
  drm/i915/gvt: destroy the allocated idr on vgpu creating failures
  drm/i915/gvt: init/destroy vgpu_idr properly
  drm/i915/gvt: dec vgpu->running_workload_num after the workload is really done
  drm/i915/gvt: fix use after free for workload
  drm/i915/gvt: remove duplicated definition
  ...

Pull x86 fix from Thomas Gleixner:
 "Restore the retrigger callbacks in the IO APIC irq chips. That
  addresses a long standing regression which got introduced with the
  rewrite of the x86 irq subsystem two years ago and went unnoticed so
  far"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioapic: Restore IO-APIC irq_chip retrigger callback

Pull smp/hotplug fix from Thomas Gleixner:
 "Remove an unused variable which is a leftover from the notifier
  removal"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Remove unused but set variable in _cpu_down()

Pull virtio/vhost fixes from Michael Tsirkin:
 "Random fixes and cleanups that accumulated over the time"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: virtio: constify virtio_config_ops structures
  virtio/s390: add missing \n to end of dev_err message
  virtio/s390: support READ_STATUS command for virtio-ccw
  tools/virtio/ringtest: tweaks for s390
  tools/virtio/ringtest: fix run-on-all.sh for offline cpus
  virtio_console: fix a crash in config_work_handler
  vhost/scsi: silence uninitialized variable warning
  vhost: scsi: constify target_core_fabric_ops structures

Pull thermal management fixes from Zhang Rui:

 - fix a regression that thermal zone dynamically allocated sysfs
   attributes are freed before they're removed, which is introduced in
   4.10-rc1 (Jacob von Chorus)

 - fix a boot warning because deprecated hwmon API is used (Fabio
   Estevam)

 - a couple of fixes for rockchip thermal driver (Brian Norris, Caesar
   Wang)

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: rockchip: fixes the conversion table
  thermal: core: move tz->device.groups cleanup to thermal_release
  thermal: thermal_hwmon: Convert to hwmon_device_register_with_info()
  thermal: rockchip: handle set_trips without the trip points
  thermal: rockchip: optimize the conversion table
  thermal: rockchip: fixes invalid temperature case
  thermal: rockchip: don't pass table structs by value
  thermal: rockchip: improve conversion error messages

Pull USB fixes from Greg KH:
 "Here are a few small USB fixes for 4.10-rc5.

  Most of these are gadget/dwc2 fixes for reported issues, all of these
  have been in linux-next for a while. The last one is a single xhci
  WARN_ON removal to handle an issue that the dwc3 driver is hitting in
  the 4.10-rc tree. The warning is harmless and needs to be removed, and
  a "real" fix that is more complex will show up in 4.11-rc1 for this
  device.

  That last patch hasn't been in linux-next yet due to the weekend
  timing, but it's a "simple" WARN_ON() removal so what could go wrong?
  :)"

Famous last words.

* tag 'usb-4.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: remove WARN_ON if dma mask is not set for platform devices
  usb: dwc2: host: fix Wmaybe-uninitialized warning
  usb: dwc2: gadget: Fix GUSBCFG.USBTRDTIM value
  usb: gadget: udc: atmel: remove memory leak
  usb: dwc3: exynos fix axius clock error path to do cleanup
  usb: dwc2: Avoid suspending if we're in gadget mode
  usb: dwc2: use u32 for DT binding parameters
  usb: gadget: f_fs: Fix iterations on endpoints.
  usb: dwc2: gadget: Fix DMA memory freeing
  usb: gadget: composite: Fix function used to free memory

Pull libnvdimm fixes from Dan Williams:
 "Two fixes:

   - a regression fix for the multiple-pmem-namespace-per-region support
     added in 4.9. Even if an existing environment is not using that
     feature the act of creating and a destroying a single namespace
     with the ndctl utility will lead to the proliferation of extra
     unwanted namespace devices.

   - a fix for the error code returned from the pmem driver when the
     memcpy_mcsafe() routine returns -EFAULT. Btrfs seems to be the only
     block I/O consumer that tries to parse the meaning of the error
     code when it is non-zero.

  Neither of these fixes are critical, the namespace leak is awkward in
  that it can cause device naming to change and complicates debugging
  namespace initialization issues. The error code fix is included out of
  caution for what other consumers might be expecting -EIO for block I/O
  errors"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, namespace: fix pmem namespace leak, delete when size set to zero
  pmem: return EIO on read_pmem() failure

Pull clk fix from Stephen Boyd:
 "One fix for Samsung Exynos524x SoCs where recent IOMMU patches have
  caused some of these clocks to turn off when they were always left on
  before"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk/samsung: exynos542x: mark some clocks as critical

Pull ARC fixes from Vineet Gupta:

 - more intc updates [Yuriv]

 - fix module build when unwinder is turned off

 - IO Coherency Programming model updates

 - other miscellaneous

* tag 'arc-4.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Revert "ARC: mm: IOC: Don't enable IOC by default"
  ARC: mm: split arc_cache_init to allow __init reaping of bulk
  ARCv2: IOC: Use actual memory size to setup aperture size
  ARCv2: IOC: Adhere to progamming model guidelines to avoid DMA corruption
  ARCv2: IOC: refactor the IOC and SLC operations into own functions
  ARC: module: Fix !CONFIG_ARC_DW2_UNWIND builds
  ARCv2: save r30 on kernel entry as gcc uses it for code-gen
  ARCv2: IRQ: Call entry/exit functions for chained handlers in MCIP
  ARC: IRQ: Use hwirq instead of virq in mask/unmask
  ARC: mmu: clarify the MMUv3 programming model

Pull powerpc fixes from Michael Ellerman:
 "Two fixes for fallout from the hugetlb changes we merged this cycle.

  Ten other fixes, four only affect Power9, and the rest are a bit of a
  mixture though nothing terrible.

  Thanks to: Aneesh Kumar K.V, Anton Blanchard, Benjamin Herrenschmidt,
  Dave Martin, Gavin Shan, Madhavan Srinivasan, Nicholas Piggin, Reza
  Arbab"

* tag 'powerpc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Ignore reserved field in DCSR and PVR reads and writes
  powerpc/ptrace: Preserve previous TM fprs/vsrs on short regset write
  powerpc/ptrace: Preserve previous fprs/vsrs on short regset write
  powerpc/perf: Use MSR to report privilege level on P9 DD1
  selftest/powerpc: Wrong PMC initialized in pmc56_overflow test
  powerpc/eeh: Enable IO path on permanent error
  powerpc/perf: Fix PM_BRU_CMPL event code for power9
  powerpc/mm: Fix little-endian 4K hugetlb
  powerpc/mm/hugetlb: Don't panic when we don't find the default huge page size
  powerpc: Fix pgtable pmd cache init
  powerpc/icp-opal: Fix missing KVM case and harden replay
  powerpc/mm: Fix memory hotplug BUG() on radix

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - Fix for timer setup on VHE machines
   - Drop spurious warning when the timer races against the vcpu running
     again
   - Prevent a vgic deadlock when the initialization fails (for stable)

  s390:
   - Fix a kernel memory exposure (for stable)

  x86:
   - Fix exception injection when hypercall instruction cannot be
     patched"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: do not expose random data via facility bitmap
  KVM: x86: fix fixing of hypercalls
  KVM: arm/arm64: vgic: Fix deadlock on error handling
  KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systems
  KVM: arm/arm64: Fix occasional warning from the timer work function